The relationship between therapeutic injections and high prevalence of hepatitis C infection in Hafizabad,Pakistan.

To determine the prevalence and routes of transmission of hepatitis C virus (HCV) infection in Hafizabad, Pakistan, we collected sera in 1993 from a geographically based random sample of residents, and in 1994 identified 15 HCV-infected individuals (cases) and 67 age and sex matched uninfected individuals (controls). Initially we approached 504 households, and collected serum from a randomly selected household member in 309 (64%). Twenty persons (6.5%) had anti-HCV antibody; 31% percent had hepatitis B core antibodies, and 4.3% had hepatitis B surface antigen. In the case-control study, persons who received more therapeutic injections (categorized as averaging 1, 2-4, 5-9 or > 10 injections per year in the previous 10 years) were more likely to be infected with HCV (odds ratio 0, 1.5, 2.5 and 6.9 respectively, P = 0.008) compared to persons averaging 0 injections per year. Efforts to limit therapeutic injections to only those that are medically indicated and that use sterile equipment are essential in order to prevent transmission of HCV.     

Human immunodeficiency virus, hepatitis B, C and D in Bangladesh's trucking industry: prevalence and risk factors

BACKGROUND: Human immunodeficiency virus (HIV) and hepatitis B and C, viral infections with shared percutaneous, mucosal and perinatal routes of transmission, are responsible for serious morbidity and mortality globally. In Bangladesh there is a dearth of research on prevalence and risk factors for these diseases. This study examines the prevalence of HIV and hepatitis (B, C, D) and risk factors associated with infection in men in Bangladesh's trucking industry (drivers and helpers on trucks), a population at risk for sexually transmitted infections. METHODS: The study population comprised 388 men (245 drivers, 143 helpers) working out of Tejgaon truck stand in Dhaka, Bangladesh. Subjects were selected through a two-tiered sampling strategy. Of 185 trucking agencies 38 were randomly selected and a of 10 subjects was recruited from each agency. Subjects were interviewed, underwent a comprehensive physical examination and had blood samples taken. Gold standard laboratory tests were conducted to detect HIV, hepatitis B, C, and D infections. To assess risk factors associated with current hepatitis B infections or being a carrier (HBsAg) and lifetime exposure to hepatitis B infection (anti-HBc), simple and multiple logistic regression analyses were performed. RESULTS: The prevalence of diseases were: HIV 0%, hepatitis C <1%, hepatitis B surface antigen 5.9%, antibody to hepatitis B core antigen 48.1% (with 5 of the 23 HBsAg positive cases testing positive for HBeAg and 18 for anti-HBe), and hepatitis D 0%. Having ever received a therapeutic injection and having had relations with a commercial sex worker (CSW) in the past year were both significantly associated with lifetime exposure to hepatitis B (anti-HBc); having received a therapeutic injection in the past year was associated with being either currently infected with hepatitis B or a carrier (HBsAg). CONCLUSIONS: The results of the study illustrate the importance of educating health care practitioners about the dangers of unsterile injections, and of educating men in the trucking industry as well as their partners (CSW in particular) about the importance of condom use, especially in high-risk sexual contacts.     

Population beliefs about the efficacy of injections in Pakistan's Sindh province

OBJECTIVE: Reused syringes have been identified as a major risk factor for hepatitis B and C in Pakistan, a country facing a growing epidemic of these infections. We conducted this study to identify factors associated with receiving at least one injection during the past 3 months in an urban and a rural area in the Sindh province of Pakistan. METHODS: A population-based cross-sectional study of individuals aged 3 months was conducted in 34 clusters in an urban and a rural setting. Information was obtained on the number of contacts with healthcare providers and the number of injections received during the past 3 months. Beliefs about the efficacy of injections were also tested. Multivariable logistic regression analysis was performed to identify factors associated with receiving at least one injection during the past 3 months. RESULTS: Of 1150 subjects who participated in the study, 848 (74%) reported having received at least one injection during the past 3 months. Seventy-one percent (815/1150) believed that injections act faster than oral drugs and relieve symptoms quickly. There was a lack of risk perception among the participants: 19% (222/1150) believed that injections involve less risk than do oral drugs. Multivariable logistic regression analysis revealed that individuals who had visited unqualified practitioners (adjusted OR=6.1; 95% CI: 2.6-14.1) or general practitioners (adjusted OR=3.4; 95% CI: 1.9-6.0) were more likely to have received an injection. Belief that 'injections act faster and relieve symptoms quickly' had a multiplicative interaction with the area of dwelling: people in rural areas who held this belief were more likely to receive injections than people who did not hold this belief and were living in urban areas. CONCLUSIONS: In Pakistan, people's lack of awareness of risks associated with injections and their strong belief in the fast action of injections are driving injection overuse. These factors are supplemented by general practitioners' and unqualified providers' inclinations to prescribe more injections. Efforts must be made to include the unqualified practitioners in any interventions aimed to reduce injection overuse in Pakistan.     

Horizontal transmission of hepatitis B virus from siblings and intramuscular injection among preschool children in a familial cohort

The authors followed 147 children from 113 families who were susceptible to hepatitis B virus infection for a total of 275 person-years. Among these children, 19 became infected with the hepatitis B virus and thus became new subclinical cases. In this cohort study, parents played a minor role in hepatitis B virus horizontal transmission. On the other hand, the estimated incidence rate ratio of hepatitis B virus infection for siblings of a hepatitis B e antigen (HBeAg) carrier was 2.8 (95% confidence interval 1.1-7.4) when compared with those children without a HBeAg sibling carrier as analyzed by multiple logistic regression. The adjusted incidence rate ratio among siblings increased with increased number of HBeAg carriers. In addition, intramuscular injections played an important role in hepatitis B virus transmission in children. It was found that 61.8% (170/275 person-years) of the children had received intramuscular injections. Most of the injections were administered at private clinics over a 2-year period. Hepatitis B virus infection showed a correlation with injection (adjusted incidence rate ratio = 3.3, 95% confidence interval 1.1-9.5) and with frequency of injections. The authors concluded that HBeAg was a valuable marker for infectivity in hepatitis B virus horizontal transmission. Furthermore, the authors found that hepatitis B virus infection is independently transmitted from sibling to sibling, and by iatrogenic injections because improperly sterilized syringes were shared in areas where hepatitis B is prevalent and intramuscular injection is common.     

A survey of HIV and HCV among female prison inmates in Portugal

HIV and hepatitis C virus (HCV) monitoring among prison inmates is instrumental in countries with concentrated HIV/AIDS epidemics. Knowledge on these dynamics in imprisoned women in Portugal is scarce. The HIV and HCV prevalence was estimated among inmates in the largest Portuguese prison for women, which holds 57% of all female inmates in Portugal, according to sociodemographic and behavioural variables and characterised attitudes towards HIV/AIDS according to serological status. Collected variables included age, education, country of birth, penal status, and accumulated time in prison. Drug injection and sharing of injection material were inquired, as well as age at first sexual intercourse. Inmates also characterised their attitudes towards HIV/AIDS. A venous blood sample was collected and tested for anti-HIV and anti-HCV antibodies. In this sample of 445 female inmates, 10% were HIV-positive, while 11% were HCV-positive. Longer imprisonment periods were associated with relatively higher HCV prevalence and women with later ages at first sexual intercourse were less frequently HIV-positive, regardless of drug injecting behaviour. HIV prevalence was 44% in women who had ever injected drugs and 6% in those who had never injected. HCV frequency was 69% among injecting drug users (IDUs) and 4% among non-IDUs. In women who injected drugs both HIV and HCV were more frequent when the number of injections was higher and when women reported sharing of injection material. Similar attitudes towards HIV/AIDS were found for HIV-positive and negative women, but those living with HIV had more tolerant positions. This study emphasizes the role of injecting drug use in the transmission of HIV and HCV in women in Portuguese prisons and reinforces the need for the systematic adoption of harm reduction measures.     

Substance abuse and high-risk needle-related behaviors among homeless youth in minneapolis: Implications for prevention

Homeless and runaway youth face a variety of health, risks, including those related to substance abuse and use of unsterile needles. During 1998–1999, we recruited 201 Minneapolis homeless youths aged 15–22 years; these youths were interviewed by experienced street outreach workers from settings where street youth were known to congregate. Respondents spent a median of 6 months in the previous year living on the streets or “couch hopping.” There were 37% who reported having 15 or more alcoholic drinks per week, 41% smoked 1 pack or more of cigarettes per day, and 37% used marijuana 3 or more times a week; 15% reported lifetime injection drug use, including 6% who used injection drugs within the previous month. Twenty percent had received a tattoo, and 18% body piercing with a needle that had not been sterilized or had been used by someone else. There were 68% who had been tested for human immunodeficiency virus (HIV), 52% for hepatitis B, and 25% for hepatitis C. There were 44% who said they did not have enough information about hepatitis B and C. Less than half (43%) received hepatitis B vaccine; however, 51% of unvaccinated youths indicated that they would receive vaccination if offered. These Midwestern homeless youths face multiple health risks, including those related to substance use and exposure to unsterile needles. Despite unsafe behaviors, many of these youths were interested in methods to protect their health, including education, knowing their HIV or viral hepatitis serostatus, and obtaining hepatitis B immunization.     

Transmission of hepatitis B, hepatitis C and human immunodeficiency viruses through unsafe injections in the developing world: model-based regional estimates

Thousands of millions of injections are delivered every year in developing countries, many of them unsafe, and the transmission of certain bloodborne pathogens via this route is thought to be a major public health problem. In this article we report global and regional estimates of the number of hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections that may occur from unsafe injections in the developing world. The estimates were determined using quantitative data on unsafe injection practices, transmission efficiency and disease burden of HBV, HCV and HIV and the prevalence of injection use obtained from a review of the literature. A simple mass-action model was used consisting of a generalized linear equation with variables accounting for the prevalence of a pathogen in a population, susceptibility of a population, transmission efficiency of the pathogen, proportion of injections that are unsafe, and the number of injections received. The model was applied to world census data to generate conservative estimates of incidence of transmission of bloodborne pathogens that may be attributable to unsafe injections. The model suggests that approximately 8-16 million HBV, 2.3-4.7 million HCV and 80,000-160,000 HIV infections may result every year from unsafe injections. The estimated range for HBV infections is in accordance with several epidemiological studies that attributed at least 20% of all new HBV infections to unsafe injections in developing countries. Our results suggest that unsafe injections may lead to a high number of infections with bloodborne pathogens. A major initiative is therefore needed to improve injection safety and decrease injection overuse in many countries.     

Unsafe injections in the developing world and transmission of bloodborne pathogens: a review

Unsafe injections are suspected to occur routinely in developing countries. We carried out a literature review to quantify the prevalence of unsafe injections and to assess the disease burden of bloodborne infections attributable to this practice. Quantitative information on injection use and unsafe injections (defined as the reuse of syringe or needle between patients without sterilization) was obtained by reviewing the published literature and unpublished WHO reports. The transmissibility of hepatitis B and C viruses and human immunodeficiency virus (HIV) was estimated using data from studies of needle-stick injuries. Finally, all epidemiological studies that linked unsafe injections and bloodborne infections were evaluated to assess the attributable burden of bloodborne infections. It was estimated that each person in the developing world receives 1.5 injections per year on average. However, institutionalized children, and children and adults who are ill or hospitalized, including those infected with HIV, are often exposed to 10-100 times as many injections. An average of 95% of all injections are therapeutic, the majority of which were judged to be unnecessary. At least 50% of injections were unsafe in 14 of 19 countries (representing five developing world regions) for which data were available. Eighteen studies reported a convincing link between unsafe injections and the transmission of hepatitis B and C, HIV, Ebola and Lassa virus infections and malaria. Five studies attributed 20-80% of all new hepatitis B infections to unsafe injections, while three implicated unsafe injections as a major mode of transmission of hepatitis C. In conclusion, unsafe injections occur routinely in most developing world regions, implying a significant potential for the transmission of any bloodborne pathogen. Unsafe injections currently account for a significant proportion of all new hepatitis B and C infections. This situation needs to be addressed immediately, as a political and policy issue, with responsibilities clearly defined at the global, country and community levels.     

Establishment of a viral hepatitis surveillance system--Pakistan, 2009-2011

Hepatitis A is thought to infect almost all persons living in Pakistan by age 15 years, and hepatitis E is responsible for sporadic infections and outbreaks. The prevalence of hepatitis B virus (HBV) infection is estimated at 2.5% and the prevalence of hepatitis C virus (HCV) infection, estimated at 4.8%, is one of the highest rates in the world. Hepatitis surveillance in Pakistan has been syndromic, failing to confirm infection, distinguish among viruses, or collect information on risk factors. To understand the epidemiology of viral hepatitis in Pakistan more clearly, the Ministry of Health (MOH) asked the Pakistan Field Epidemiology and Laboratory Training Program (FELTP) to establish a hepatitis sentinel surveillance system in five large public hospitals in four provinces and Islamabad Capital Territory. This report describes the implementation of the viral hepatitis surveillance system in Pakistan and summarizes major findings from June 2010 through March 2011. A total of 712 cases of viral hepatitis were reported; newly reported HCV infection accounted for 53.2% of reported cases, followed by acute hepatitis A (19.8%), acute hepatitis E (12.2%), and newly reported HBV infection (10.8%). A history of health-care--related exposures, particularly receipt of therapeutic injections and infusions, commonly were reported by persons infected with HBV and HCV, and most patients reported drinking unboiled water. These findings point to the need for improved provider and community education about risks associated with unsafe injections, strengthening infection control practices in health facilities, increasing hepatitis B vaccination coverage, and improving access to clean drinking water in Pakistan.     

The occurrence of hepatitis B and C viruses in Pakistani patients with chronic liver disease and hepatocellular carcinoma.

To study the occurrence of hepatitis B virus (HBV) and hepatitis C virus (HCV) in patients with chronic liver disease (CLD) and hepatocellular carcinoma (HCC) in Pakistan, blood samples from 105 sequential patients with biopsy-proven CLD (n = 82) and HCC (n = 23) were tested for HBV and HCV markers. Of the 105, 87 (83%) had evidence of hepatitis B exposure, 58 (55%) were positive for hepatitis B surface antigen (HBsAg), 23 (22%) had hepatitis C antibodies and 25 (24%) had detectable HCV RNA. Significantly more patients with HCC had evidence of HBV exposure in the absence of HCV markers (49/82 vs. 20/23, odds ratio 4.49, 95% CI 1.17-25.16). The proportion of patients positive for HBsAg with no HCV markers was also significantly higher in the HCC group (34/82 vs. 18/23, odds ratio 5.08, 95% CI 1.59-18.96). There were more patients with only HCV markers in the CLD group than the HCC group but the difference was not statistically significant (19/82 vs. 1/23, odds ratio 6.63, 95% CI 0.93-288.01). A modified non-isotopic restriction fragment length polymorphism study on PCR products was used to investigate the epidemiology of HCV genotypes in Pakistan. Due to depletion of the initial samples, a second series of specimens collected one year afterwards was used. Fifteen out of 40 samples had amplifiable product and all were identified as type 3. A commercial serological typing method on the same samples also confirmed that type 3 was the predominant HCV genotype in Pakistan.     

Human immunodeficiency virus and hepatitis C virus infections among patients attending sexually transmitted disease clinics, Regional 2, Thailand

A cross-sectional study of 400 patients attending sexually transmitted disease (STD) clinics at The Venereal Diseases and AIDS Centers, Regional 2, Thailand, was conducted from January to December 1996 in order to investigate the antibody prevalence to human immunodeficiency virus (HIV) and hepatitis C virus (HCV) and to describe some epidemiological characteristics among HIV and HCV co-infected individuals. The studied patients were interviewed and their blood specimens were collected for determining anti-HIV and anti-HCV antibodies. The results revealed that the prevalence of anti-HIV among studied patients was 25%, while 7.5% were positive for anti-HCV. The positivity of both antibodies present in the same individuals was 3.3% (13/400 cases). The highest prevalences of anti-HIV, anti-HCV and both antibodies were found in studied patients aged 20 years or less. Patients with primary education, or lower, had relatively higher prevalence of anti-HIV and/or anti-HCV than those with higher level education. A relatively higher prevalence was found among commercial sex workers and labourers. Among 13 HIV and HCV co-infected individuals, there were four cases who had histories of sexual contact without condom use, but no history of parenteral contact. The rest (9/13) had histories of both parenteral contact and sexual contact without condom use.     

Seroprevalence of hepatitis B and C in a Merseyside hospital for the mentally handicapped.

This study reports the prevalence of antibodies to hepatitis B virus (HBV) and C virus (HCV), and the frequency of potential exposure to these viruses among patients and staff in six long-stay wards of a hospital caring for mentally handicapped adults from the Mersey region. A retrospective survey of risk behaviour among 134 patients and questionnaire survey of 75 nursing staff was performed. Serum samples from both groups were tested for HBV markers and patient sera for antibodies to HCV by enzyme-linked immunosorbent assay (ELISA). None of the 102 patients tested had antibodies against HCV, although 17 had detectable antibody to HBV core (anti-HBc). Seven out of the 17 were positive for HBV surface antigen. None was positive for IgM antibody to HBV core. Only 1 out of 61 staff had anti-HBc and none was positive for surface antigen. Twenty-nine of 75 (39%) staff reported bites sufficient to break the skin and 52 (69%) significant other injuries from patients; 25 (31%) of staff had not received HBV vaccination. None of the patients had received HBV vaccine. We conclude that HCV does not appear to be a major hazard in this closed community but the prevalence of HBV markers indicating past exposure among patients is high, vaccine uptake is incomplete and incidents which may allow viral transmission are frequent.     

Risk factors for hepatitis B in an outbreak of hepatitis B and D among injection drug users

During January-April, 2000, 12 cases of acute hepatitis B were reported in Pierce County, Washington, compared with seven in all of 1999. Seven (58.3%) case patients were injection drug users (IDUs), three of whom were coinfected with hepatitis D virus (HDV) and died of fulminant hepatitis. Vaccination clinics were implemented at the local health department and needle exchange program to control the outbreak. We investigated this outbreak to determine risk factors for hepatitis B virus (HBV) transmission among IDUs. Hepatitis B cases were ascertained through routine surveillance and prevaccination testing at vaccination clinics. We conducted a case-control study comparing IDU case patients with HBV-susceptible IDUs identified at the vaccination clinics. Fifty-eight case patients were identified during January-December, 2000, 20 (34.5%) of whom were coinfected with HDV. Thirty-eight case patients (65.5%) reported current IDU. In the case-control study, the 17 case patients were more likely than the 141 controls to report having more than one sex partner [odds ratio (OR) =4.8, 95% confidence interval (CI) =1.5-15.0], injecting more than four times a day (OR = 4.5, 95% CI =1.2-15.6) and sharing drug cookers with more than two people (58.8% vs. 14.0%, OR =14.0, 95% CI =2.4-81.5). Results were similar after controlling for syringe sharing in multivariable analysis. IDUs should be vaccinated against hepatitis B and should be advised against sharing drug injection equipment.     

Routine hepatitis B vaccination in a clinic for sexually transmitted diseases.

Patients were assigned to one of two vaccine schedules to assess the feasibility of vaccinating a sexually transmitted disease clinic population against hepatitis B virus. Of 1386 patients entering an inner-city clinic between June and July 1990, 611 (44%) accepted a first dose of vaccine. Twenty-one percent of all susceptible patients received at least two doses of vaccine. Annualizing these findings shows that an ongoing program could prevent 636 hepatitis B virus infections per year. Although a significant proportion of sexually transmitted disease clinic patients can be successfully vaccinated, strategies for preventing hepatitis B virus infections in this high-risk population must consider patient behavior as well as vaccine efficacy.     

Viral hepatitis vaccination in an opioid treatment program: Hartford, Connecticut, 2002-2005

Hartford Dispensary, a private, not-for-profit behavioral health care organization specializing in opioid treatment program services, serves more than 4,200 clients per day in seven licensed facilities. In May 2002, the Dispensary began offering free combined hepatitis A and B vaccine for all eligible clients in two Hartford clinics. Initial eligibility criteria required a client to be hepatitis C antibody positive, hepatitis B virus (HBV) surface antigen (HBsAg) negative, not pregnant, and not have a contraindication due to a medical condition. From May 2002 through April 2005, 5,419 doses of combined vaccine were given. Of the 2,072 clients who received a first dose, 92% (1,914) received the second dose and 69% (1,433) completed the series. Long treatment duration, frequent client visits, availability of medical staff, and counseling support contributed to high rates of combined vaccine series completion in the two programs. Opioid treatment programs appear to be good settings in which to provide hepatitis vaccination for high-risk adults.     

Injections in health care settings: a risk factor for acute hepatitis B virus infection in Karachi,Pakistan

A case control study was conducted to identify the association of therapeutic injections with acute hepatitis B virus (HBV) infection in Karachi, Pakistan. We enrolled 67 cases of acute HBV infection (IgM anti-HBc positive) and 247 controls (anti-HBc negative) from four hospitals of Karachi during July 2000-June 2001. Exposure to various risk factors during the period relevant to the incubation period of HBV was recorded both from cases and controls using a structured questionnaire. Multivariate logistic regression analysis of the data showed that cases were more likely to have received one injection (OR = 4.0; 95 % CI 1.4, 11.1), or more than one injection (OR = 6.3; 95 % CI 3.2, 12.4) compared to controls. The estimated population attributable risk (PAR) for therapeutic injections was 53%. Also the cases compared to controls were more likely to have household size of seven or more (OR = 1.9; 95 % CI 0.95, 3.9). This study showed that unsafe therapeutic injections appear to be the major risk factor for acute HBV infection and needs immediate focus from public health stand point.     

Reduced risk of hepatitis B and hepatitis C among injection drug users in the Tacoma syringe exchange program.

OBJECTIVES. This case-control study examined the association between syringe exchange use and hepatitis B and C in injection drug users. METHODS. Case patients included 28 injection drug users with acute hepatitis B and 20 with acute hepatitis C reported to the health department in a sentinel hepatitis surveillance county; control subjects were injection drug users with no markers of exposure to hepatitis B or C (n = 38 and 26, respectively) attending health department services during the same period. Data were abstracted from clinic records. RESULTS. Seventy-five percent of case patients with hepatitis B and 26% of control subjects had never used the exchange; similar proportions were found for the hepatitis C case and control groups. After adjustment for demographic characteristics and duration of injecting drugs, nonuse of the exchange was associated with a sixfold greater risk of hepatitis B (odds ratio [OR] = 5.5; 95% confidence interval [CI] = 1.5, 20.4) and a sevenfold greater risk of hepatitis C (OR = 7.3; 95% CI = 1.6, 32.8). CONCLUSIONS. The results suggest that use of the exchange led to a significant reduction in hepatitis B and hepatitis C in the county and may have also prevented a substantial proportion of human immunodeficiency virus infections in injection drug users.     

Audit of bloodborne virus infections in injecting drug users in general practice

Two hundred and ninety patients attending a single general practice in Edinburgh were known to have used illegal drugs, 145 of whom were identified as past or present injectors. Data on bloodborne virus infections and immunisation against hepatitis B virus (HBV) were gathered during 1998, attempts were made to improve the level of testing for bloodborne viruses and immunisation against HBV, and follow up was carried out between October 1999 and February 2000. One hundred and fifteen patients were studied in detail. Evidence of previous HBV infection was found in 31 of 71 tested in 1998 (44%) and 40 of 99 tested at follow up (40%). In 1998 54 out of the 75 tested for hepatitis C antibodies (72%) were positive compared with 73 out of 108 (68%) at follow up. Twenty-six of the 80 tested for HIV antibodies were positive in 1998 (33%) and 26 of 105 at follow up (25%). Large numbers of injecting drug users in our study were found to be not immune to hepatitis B and required immunisation. An abbreviated protocol for immunisation was devised, including post vaccination checks and boosting as necessary. Hepatitis C testing was requested after counselling in most cases, resulting in important and positive interventions. Prevention opportunities for all three bloodborne viruses were identified.     

Multiple infections and associated risk factors among non-injecting cocaine users in Argentina

The aim of this study was to estimate the seroprevalence rates of human immunodeficiency virus (HIV), hepatitis B virus (HBV, core antibody), hepatitis C virus (HCV), and syphilis infections and analyze associated risk factors among 504 non-injecting cocaine users (NICU) in Buenos Aires, Argentina. Participants were interviewed in face-to-face sessions through a short structured questionnaire. Using venipuncture, 10 mL of blood was collected. Seroprevalence rates were: HIV (6.3%), HBV (9%), HCV (7.5%), and VDRL (4.2%). The risk of being infected with HIV, HBV, and HCV was significantly associated with having had a sex partner who was either a drug injector or who was known to be HIV positive. HIV and HCV infections were associated with former imprisonment, and HCV was associated with having been tattooed. Because of the rising number of NICU and the multiple infections detected, it is essential to implement prevention strategies focused on this population.